Recreational vehicles such as motor homes, trailers, and the like often include among their amenities television sets, FM stereo receivers, and other electronic equipment receiving atmospheric transmitted signals. Various types of antennas have been developed for recreational vehicle use having characteristics particularly suitable for this type of installation, a typical example being shown in the assignee's U.S. Pat. No. 3,665,477.
Dipole antennas are particularly advantageous as used with television receivers, but a relatively inexpensive efficient dipole antenna for recreational vehicle use utilizing extendable and retractable telescoping antenna assemblies has not previously been available, and the invention pertains to a dipole antenna particularly suitable for recreational vehicle installations. While extendable and retractable dipole antennas have been known as shown in U.S. Pats. Nos. 2,569,810 and 2,778,017, and while it is known to extend and retract telescoping antenna elements with flexible actuators as shown in U.S. Pats. Nos. 2,327,163; 2,344,490 and 4,426,650, antenna structure has not previously been available which is capable of withstanding the rugged and versatile service required in a recreational vehicle installation, nor has an adjustable and directional dipole antenna been available for recreational vehicles wherein operation of the antenna is possible by remote control, or by manual actuation within the vehicle interior.
It is an object of the invention to provide an adjustable dipole antenna for recreational vehicle use wherein the extension and retraction of dipole antenna assemblies, and rotation of these assemblies may be remotely achieved within the interior of the vehicle.
Another object of the invention is to provide a fully adjustable dipole antenna wherein extendable and retractable telescoping antenna assemblies are simultaneously operated by flexible actuators through a common driveshaft.
An additional object of the invention is to provide an adjustable dipole antenna particularly suitable for recreational vehicle installations which is capable of withstanding the vibration and rugged usage of such installations, is readily installable requiring a minimum of technical skills, dependable in operation, and easily assembled.
Yet a further object of the invention is to provide a dipole antenna having telescoping antenna assemblies operated by flexible actuators mounted upon reels wherein the reel construction assures uniform operating characteristics under adverse conditions and wherein the actuator is smoothly discharged from the reel and rewound thereon without binding and kinking.
A further object of the invention is to provide a dipole antenna particularly suitable for recreational vehicle installations wherein, with minor modifications, the operating and adjustment functions of the antenna may be remotely controlled from the vehicle interior by either manual or electrically operated apparatus.
In the practice of the invention the antenna includes a vertically disposed column adapted to be rotatably mounted upon the vehicle roof or similar vehicle structure for rotation about a substantially vertical axis. At its upper end, the column is provided with a support for a pair of telescoping dipole antenna assemblies each consisting of several tubular telescoping elements which extend in substantially opposite directions from the column. Interiorly, the antenna assemblies include a flexible actuator, such as a synthetic plastic rod attached to the outermost antenna element at one end, and the other end being affixed to a reel rotatably mounted adjacent the column upper end. Each actuator is mounted upon a separate reel, and the reels include gear teeth engaging a pinion mounted upon a shaft extending through the column whereby rotation of the shaft simultaneously rotates the reels producing simultaneous retraction and extension of the antenna assemblies.
The lower end of the column is mounted within a housing affixed to the vehicle roof, and the reel operating shaft extends into this housing. In the manually operated embodiment a concentric control knob and crank coaxially aligned with the column extend through the vehicle roof for access within the vehicle interior. The knob is attached to the column for producing selective rotation of the column about its vertical axis, and the crank is attached to the reel driveshaft for producing rotation of the reels to extend and retract the antenna assemblies.
If the remote control of the antenna operations are electrically produced, electric motors located within the housing and controlled by switches within the vehicle interior rotate the column and reel driveshaft to extend and retract the antenna assemblies and rotate the column for directional adjustment.
Smooth dispensing of the flexible antenna actuators from their associated reel, and rewinding thereon, is assured by dispensing the actuator rod from the reel at the inner reel end, and utilizing a conical actuator receiving surface in spaced radial relationship to a complementary actuator retaining surface thereby preventing overlapping of the actuator rod during antenna retraction and preventing actuator malfunctions.